Design and Process Sensitivity of a Two-Stage 6 - 18-GHz Monolithic Feedback Amplifier

The design of a 6-18-GHz two-stage monolithic feedback amplifier is discussed, and the critical process and FET parameters are identified. Variations in circuit performance experienced during a pilot production run are correlated with the predictions of a sensitivity analysis. Five circuit model parameters were selected for study substrate height, GaAs sheet resistance, gate-source capacitance, transconductance, and drain-source resistance. Measured results show the importance of substrate height and sheet resistance in the control of gain flatness. An example on-slice RF performance distribution is presented, showing the suitability of the circuit and fabrication process for high-volume production.